A method for measuring pole tower using unmanned aerial vehicle

Abstract

The invention discloses a method for measuring a pole tower by an unmanned aerial vehicle, which belongs to the technical field of power system automation. The method comprises the following steps: first, based on the measurement requirements of the longitude and latitude of the pole tower, obtaining an image of the pole tower in the forward direction of the unmanned aerial vehicle; second, based on the measurement requirements of the cross arm length of the pole tower and the height of the pole tower, obtaining an image of the pole tower in the vertical direction by the unmanned aerial vehicle; third, processing the data obtained in the second step to obtain the length of the cross arm; the invention uses a small number of sensors, a simple system, high reliability, high precision, and relatively simple subsequent image processing; the complexity of subsequent image processing is greatly simplified; the maximum potential of unmanned aerial vehicle power inspection is fully utilized, the number of single-flight inspection equipment and the quality of equipment image acquisition are greatly increased, more pole tower data can be mastered, and the quality and efficiency of unmanned aerial vehicle power inspection are significantly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power system automation, and more specifically to a method for measuring a pole tower using an unmanned aerial vehicle. Background Art

[0002] Due to the large scale of transmission lines, cross-regional distribution, wide coverage, and the fact that most of the lines use bare wires, they are exposed to the natural environment for a long time and are affected by various harsh factors, which can easily lead to serious aging or even damage of some equipment, resulting in safety hazards. If not discovered and eliminated in time, it may develop into various faults, which in turn affect the normal operation of the transmission system. In order to ensure the normal operation of the power grid, a large amount of resources are consumed every year to maintain the power lines in order to eliminate hidden dangers in time, prevent further deterioration, and ensure the normal, stable and safe operation of the lines.

[0003] Traditional inspection methods mainly rely on manual inspections, where maintenance personnel rely on vehicles or walking, using telescopes to inspect line facilities. The work is intensive, the environment is harsh, the work efficiency is low, and it is affected by the visual and geographical environment. Missed inspections and false inspections often occur, making it difficult to obtain satisfactory inspection results.

[0004] At the end of the 20th century, my country began to use drones for line inspections. Compared with manual inspections, drones are small and easy to carry. Their inspection methods have the advantages of low cost, high efficiency, and no influence from the natural environment. They can be remotely controlled by hand or fly autonomously based on their own programs. While ensuring the reliability and safety of inspections, they can also be equipped with infrared and ultraviolet imagers, which greatly improves the efficiency of line inspections. However, in the process of inspections, it is necessary to accurately obtain detailed data of the towers. The existing measurement methods have certain defects, and the measurement accuracy is difficult to guarantee. At present, the sensors used for distance measurement are of many types, large in number, complex in system, low in reliability, poor in accuracy, and the subsequent image processing is relatively complex. Summary of the invention

[0005] In view of the problems existing in the prior art, the object of the present invention is to provide a method for measuring pole towers using an unmanned aerial vehicle, which uses fewer distance measuring instruments, has a simple calculation method, and is highly accurate and reliable.

[0006] To solve the above problems, the present invention adopts the following technical solutions:

[0007] A method for measuring a pole tower using an unmanned aerial vehicle comprises the following steps:

[0008] Step 1: Based on the measurement requirements of the longitude and latitude of the tower, obtain the image of the tower in the direction of the drone;

[0009] Step 2: Based on the cross arm length of the tower and the height measurement requirements of the tower, obtain the image of the tower in the vertical direction by the drone;

[0010] Step 3: Process the data obtained in step 2 to obtain the length of the crossarm.

[0011] Preferably, the drone is equipped with a monocular camera.

[0012] Preferably, the step 1 requires taking N photos of the pole tower in the forward direction of the drone, and obtaining the distance between the aircraft and the center point of the pole tower by comparing the differences of the N photos of the pole tower.

[0013] Preferably, the step 2 requires taking N photos of the pole tower in the vertical direction, and then raising the pole tower to a certain height and taking N more photos of the pole tower.

[0014] Preferably, the number N of the N photos in step 1 and step 2 is determined as follows:

[0015] Since three sets of data can be obtained by comparing the three photos, these three sets of data can be used to calculate three unknowns and take the average value to get the final parameters;

[0016] The process is set as follows:

[0017] Photographing the entire tower:

[0018] (1) Take three photos in the vertical and forward directions (one photo every 3 (N) meters to determine the tower parameters)

[0019] (2) Take three photos horizontally (one photo every 3 (N) meters to determine the tower parameters)

[0020] Shooting the center point of the tower:

[0021] (1) The drone flies to the top of the tower head and takes photos vertically downward to verify the longitude and latitude of the tower.

[0022] Shooting the side of the tower:

[0023] Nine photos per phase

[0024] (1) Take three photos vertically (one photo every 1 (N) meter to determine the tower parameters)

[0025] (2) Take three photos horizontally (one photo every 1 (N) meter to determine the tower parameters)

[0026] Preferably, the step three is as follows:

[0027] Calculate the length of the crossarm:

[0028] (1) When the angle between the photographing plane and the tower plane is zero, that is, the drone lens is parallel to the tower plane;

[0029] S1: The drone takes a photo at an appropriate position on the tower, keeping the photo magnification (assuming the lens resolution is M*N) unchanged, and moves the drone vertically upward or horizontally for a distance to take another photo;

[0030] S2: Calculate the ratio of the actual object to the photo based on the displacement of the same point of the tower in the two photos, and then determine the relevant parameters of the tower based on the difference between the pixels in the photos;

[0031] S3: Figure 1 and Figure 2 As shown, 10 is the wire hanging point, 21 is the drone, the distance between the drone lens and the wire hanging point is L, the height of the drone is H2, and the height of the drone hanging point from the ground is H1. The spatial position coordinates of the drone at this time are (x1, y1, h1), and a photo is taken at this time. The drone is lifted up a certain height, and the position coordinates of the drone become (x2, y2, h2), and another photo is taken at this time;

[0032] S4: For the drone, the displacement is △h=h2-h1, and for a same pixel point of the drone hanging point, its longitudinal displacement is △N=N2-N1;

[0033] S5: Define P = (h2-h1) / (N2-N1), where P is the vertical pixel magnification;

[0034] S6: Measure the difference in pixel displacement △x between the two farthest points of the tower in the photo, and the length of the corresponding cross arm can be obtained as X = △x*P;

[0035] S7: By moving the drone left and right to take these two photos, the horizontal pixel magnification Q = (l2-l1) / (M2-M1) can be determined, where l1 and l2 are the positions of the first and second photo points of the aircraft, and M1 and M2 are the positions of the same pixel points in the photos;

[0036] S8: From this, the actual length of the horizontal object in the photo, such as the length of the cross arm, can be calculated, X = △x*Q.

[0037] (2) When the angle between the photographing plane and the tower plane is not zero, that is, the drone lens is not parallel to the tower plane;

[0038] The heights of the underground crossarms and the center of the tower are not equal in the photo because the distances of the three points from the lens are different, so the magnifications are different.

[0039] Process 1: By using the difference in magnification, we can get:

[0040] |A1-A2|=B|P1-P2|

[0041] Process 2: Determine the angle between the lens and the tower plane:

[0042]

[0043] Step 3: Determine the length of the crossarm using the integral method

[0044]

[0045]

[0046]

[0047] So the cross arm length at this time is:

[0048] Beneficial effects:

[0049] Compared with the prior art, the advantages of the present invention are:

[0050] The sensors used are of few types and in small quantities, the system is simple, the reliability and accuracy are high, and the subsequent image processing is relatively simple; this greatly simplifies the complexity of subsequent image processing; it fully taps the maximum potential of UAV power inspections, greatly increases the number of inspection equipment per flight and the quality of equipment image acquisition, can grasp more pole tower data, and significantly improves the quality and efficiency of UAV power inspections. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Attached Figure 1 This is a schematic diagram of the UAV ranging of the present invention;

[0052] Attached Figure 2 A schematic diagram of the height change of the UAV of the present invention when measuring distance;

[0053] Attached Figure 3 It is a schematic diagram of calculating the cross arm length of the present invention. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0055] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0056] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] A method for measuring a pole tower using an unmanned aerial vehicle comprises the following steps:

[0058] Step 1: Based on the measurement requirements of the longitude and latitude of the tower, obtain the image of the tower in the direction of the drone;

[0059] Step 2: Based on the cross arm length of the tower and the height measurement requirements of the tower, obtain the image of the tower in the vertical direction by the drone;

[0060] Step 3: Process the data obtained in step 2 to obtain the length of the crossarm.

[0061] Preferably, the drone is equipped with a monocular camera.

[0062] Preferably, the step 1 requires taking N photos of the pole tower in the forward direction of the drone, and obtaining the distance between the aircraft and the center point of the pole tower by comparing the differences of the N photos of the pole tower.

[0063] Preferably, the step 2 requires taking N photos of the pole tower in the vertical direction, and then raising the pole tower to a certain height and taking N more photos of the pole tower.

[0064] Preferably, the number N of the N photos in step 1 and step 2 is determined as follows:

[0065] Since three sets of data can be obtained by comparing the three photos, these three sets of data can be used to calculate three unknowns and take the average value to get the final parameters;

[0066] The process is set as follows:

[0067] Photographing the entire tower:

[0068] (1) Take three photos in the vertical and forward directions (one photo every 3 (N) meters to determine the tower parameters)

[0069] (2) Take three photos horizontally (one photo every 3 (N) meters to determine the tower parameters)

[0070] Shooting the center point of the tower:

[0071] (1) The drone flies to the top of the tower head and takes photos vertically downward to verify the longitude and latitude of the tower.

[0072] Shooting the side of the tower:

[0073] Nine photos per phase

[0074] (1) Take three photos vertically (one photo every 1 (N) meter to determine the tower parameters)

[0075] (2) Take three photos horizontally (one photo every 1 (N) meter to determine the tower parameters)

[0076] Preferably, the step three is as follows:

[0077] Calculate the length of the crossarm:

[0078] (1) When the angle between the photographing plane and the tower plane is zero, that is, the drone lens is parallel to the tower plane;

[0079] S1: The drone takes a photo at an appropriate position on the tower, keeping the photo magnification (assuming the lens resolution is M*N) unchanged, and moves the drone vertically upward or horizontally for a distance to take another photo;

[0080] S2: Calculate the ratio of the actual object to the photo based on the displacement of the same point of the tower in the two photos, and then determine the relevant parameters of the tower based on the difference between the pixels in the photos;

[0081] S3: Figure 1 and Figure 2 As shown, 10 is the wire hanging point, 21 is the drone, the distance between the drone lens and the wire hanging point is L, the height of the drone is H2, and the height of the drone hanging point from the ground is H1. The spatial position coordinates of the drone at this time are (x1, y1, h1), and a photo is taken at this time. The drone is lifted up a certain height, and the position coordinates of the drone become (x2, y2, h2), and another photo is taken at this time;

[0082] S4: For the drone, the displacement is △h=h2-h1, and for a same pixel point of the drone hanging point, its longitudinal displacement is △N=N2-N1;

[0083] S5: Define P = (h2-h1) / (N2-N1), where P is the vertical pixel magnification;

[0084] S6: Measure the difference in pixel displacement △x between the two farthest points of the tower in the photo, and the length of the corresponding cross arm can be obtained as X = △x*P;

[0085] S7: By moving the drone left and right to take these two photos, the horizontal pixel magnification Q = (l2-l1) / (M2-M1) can be determined, where l1 and l2 are the positions of the first and second photo points of the aircraft, and M1 and M2 are the positions of the same pixel points in the photos;

[0086] S8: From this, the actual length of the horizontal object in the photo, such as the length of the cross arm, can be calculated, X = △x*Q.

[0087] (2) When the angle between the photographing plane and the tower plane is not zero, that is, the drone lens is not parallel to the tower plane;

[0088] The heights of the underground crossarms and the center of the tower are not equal in the photo because the distances of the three points from the lens are different, so the magnifications are different.

[0089] Process 1: By using the difference in magnification, we can get:

[0090] |A1-A2|=B|P1-P2|

[0091] Process 2: Determine the angle between the lens and the tower plane:

[0092]

[0093] Step 3: Determine the length of the crossarm using the integral method

[0094]

[0095]

[0096]

[0097] So the cross arm length at this time is:

[0098] The above are only preferred specific embodiments of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and improved concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for measuring a pole tower using an unmanned aerial vehicle, characterized in that: The following steps are involved: Step 1: Based on the measurement requirements of the longitude and latitude of the tower, obtain the image of the tower in the direction of the drone; Step 2: Based on the cross arm length of the tower and the height measurement requirements of the tower, obtain the image of the tower in the vertical direction by the drone; Step 3: Process the data obtained in step 2 to obtain the length of the cross arm; The step three is as follows: Calculate the length of the crossarm: (1) When the angle between the photographing plane and the tower plane is zero, that is, the drone lens is parallel to the tower plane; S1: The drone takes a photo at an appropriate position on the tower, keeping the photo magnification unchanged, and then moves the drone vertically upward or horizontally for a distance to take another photo; S2: Calculate the ratio of the actual object to the photo based on the displacement of the same point of the tower in the two photos, and then determine the relevant parameters of the tower based on the difference in pixels in the photos; S3: The distance between the drone lens and the wire hanging point is L, the height of the drone is H2, and the height of the drone hanging point from the ground is H1; the spatial position coordinates of the drone at this time are (x1, y1, h1), and a photo is taken at this time; the drone is lifted up a certain height, and the position coordinates of the drone become (x2, y2, h2), and another photo is taken at this time; S4: For the drone, the displacement is △h = h2-h1, and for the same pixel point of the drone hanging point, its longitudinal displacement is △N = N2-N1; S5: define P = (h2-h1) / (N2-N1), where P is the vertical pixel magnification; S6: Measure the pixel displacement difference △x between the two farthest points of the tower in the photo, and the length of the corresponding cross arm can be obtained as X=△x*P; S7: By moving the drone left and right to take these two photos, the horizontal pixel magnification Q = (l2-l1) / (M2-M1) can be determined, where l1 and l2 are the positions of the first and second photo points of the aircraft, and M1 and M2 are the positions of the same pixel points in the photos; S8: From this, the actual length of the horizontal object in the photo can be calculated, that is, the length of the cross arm X = △x*Q; (2) When the angle between the photographing plane and the tower plane is not zero, that is, the drone lens is not parallel to the tower plane; The heights of the underground crossarms and the center of the tower are not equal in the photo because the distances of the three points from the lens are different, so the magnifications are different. Process 1: By using the difference in magnification, we can get: |A1-A2|=B|P1-P2| Process 2: Determine the angle between the lens and the tower plane: Step 3: Determine the length of the crossarm using the integral method So the cross arm length at this time is:

2. A method for measuring a pole tower by using an unmanned aerial vehicle according to claim 1, characterized in that: The unmanned aerial vehicle is equipped with a monocular camera.

3. The method for measuring a pole tower by using an unmanned aerial vehicle according to claim 1, characterized in that: The step 1 requires taking N photos of the pole tower in the direction of the drone's advance, and obtaining the distance between the aircraft and the center point of the pole tower by comparing the differences of the N photos of the pole tower.

4. The method for measuring a pole tower by using an unmanned aerial vehicle according to claim 1, characterized in that: The step 2 requires taking N photos of the pole tower in the vertical direction, and then raising the pole tower to a certain height and taking N more photos of the pole tower.

5. The method for measuring a pole tower by using an unmanned aerial vehicle according to claim 1, characterized in that: The number N of N photos in step 1 and step 2 is determined as follows: Since three sets of data can be obtained by comparing the three photos, these three sets of data can be used to calculate three unknowns and take the average value to get the final parameters; The process is set as follows: Photographing the entire tower: (1) Take three photos in the vertical and forward directions, i.e. one photo every 3 meters, to determine the tower parameters; (2) Take three photos horizontally, one photo every 3 meters, to determine the tower parameters; Shooting the center point of the tower: (1) The drone flies to the top of the tower head and takes photos vertically downward to verify the longitude and latitude of the tower; Shooting the side of the tower: Nine photos per phase (1) Take three photos vertically, one photo every 1 meter, to determine the tower parameters; (2) Take three photos horizontally, one photo every 1 meter, to determine the tower parameters.

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